#include <bits/stdc++.h>
#define int long long
#define double long double
using namespace std;
const int MOD = 1000000007;
const int INF = 1e14;
using Graph = vector<vector<int>>;

signed main(){
  int H, W;
  cin >> H >> W;
  map<int, int> num;
  for( int i = 0; i < H; i++ ){
    for( int j = 0; j < W; j++ ){
      int p;
      cin >> p;
      num[p]++;
    }
  }

  int now = 0;
  for( int i = 0; i < H; i++ ){
    for( int j = 0; j < W; j++ ){
      while( num[now] == 0 ){
        now++;
      }
      cout << now << " ";
      num[now]--;
    }
    cout << endl;
  }
}